Temperature and Humidity Uniformity Tests
Temperature and humidity uniformity tests assess how consistently environmental conditions are maintained across a controlled space. These tests are critical in cleanrooms, pharmaceutical manufacturing, laboratories, hospitals, food storage, and electronics production, where fluctuations can impact product quality, process stability, and regulatory compliance.

1. Purpose of Temperature & Humidity Uniformity Testing
Ensures compliance with industry standards (ISO 14644, WHO GMP, FDA cGMP, USP 797, ASHRAE, ANSI/IES, and ASTM).
Prevents contamination and degradation in cleanrooms, pharma, and healthcare.
Ensures equipment and process stability in temperature-sensitive environments.
Improves worker comfort and safety in regulated workspaces.

2. Key Parameters for Testing
Temperature Uniformity (°C or °F) → Measures how evenly temperature is distributed.
Relative Humidity (RH%) → Ensures moisture levels are controlled.
Dew Point (°C/°F) → Indicates condensation risk.
Airflow & Ventilation Efficiency → Affects temperature/humidity stability.

3. Recommended Temperature & Humidity Ranges
Application
Temperature Range (°C)
Relative Humidity (RH%)
Uniformity Tolerance
Cleanrooms (ISO 5-8, Pharma)
18 – 24
40 – 60
±1°C, ±5% RH
Hospitals (ICUs, ORs, Pharmacies)
20 – 24
30 – 60
±1°C, ±5% RH
Biotech & Pharma Storage
15 – 25
35 – 65
±2°C, ±5% RH
Food Processing & Storage
0 – 10
60 – 85
±2°C, ±5% RH
Electronics Manufacturing
20 – 23
35 – 55
±1°C, ±3% RH

4. Temperature & Humidity Uniformity Test Procedure
a. Equipment Required
Data Loggers / Digital Thermohygrometers – For continuous temperature & humidity monitoring.
Infrared Thermometer – For spot-check temperature measurements.
Psychrometer – Measures humidity with wet/dry bulb readings.
Grid Layout Plan – Defines measurement points within the room.
b. Test Steps
Establish a measurement grid (based on room size & standards).
Place sensors at multiple locations (center, corners, high/low points).
Measure readings at set intervals (e.g., every 5-10 minutes for 24 hours).
Analyze variations to determine uniformity across the space.
Compare results with industry requirements.

5. Pass/Fail Criteria for Uniformity
Pass: Variations remain within specified tolerance limits (e.g., ±1°C, ±5% RH).
Fail: Differences exceed allowed thresholds, requiring adjustments.

6. Corrective Actions for Non-Uniform Conditions
Optimize HVAC & airflow patterns for better temperature stability.
Check for leaks or thermal bridges affecting insulation.
Calibrate humidity control systems to maintain RH levels.
Install additional sensors in problem areas for better monitoring.

7. Applications of Temperature & Humidity Uniformity Tests
Cleanrooms & Pharmaceutical Facilities → Ensures compliance & contamination control.
Hospitals & Operating Rooms → Prevents infections & equipment malfunctions.
Food & Beverage Industry → Maintains freshness & prevents spoilage.
Semiconductor & Electronics Manufacturing → Prevents static discharge & defects.
Would you like a detailed testing protocol or data analysis methods for uniformity testing?